Final meat tenderness is determined by the rate and extent
of postmortem proteolysis of key myofi brillar proteins
in the muscle. The calpains system is the principal contributor
to postmortem proteolysis which is related to meat tenderness.
Numerous studies have shown that the main role among
the calpain system plays a calpain I and calpastatin. However,
a number of subsequent studies have provided evidence that
proteasome could contribute to meat tenderisation. Also,
it is possible that caspases are responsible for postmortem
proteolysis and meat tenderization. This requires further investigation
and confi rmation in next works.